Here are my own first impressions of El Capitan on my six year old early 2009 white MacBook. Specs 2.0GHz Core 2 Duo / 4GB 667MHz DDR2 SDRAM / NVIDIA GeForce 9400M 256MB / 240GB PNY SSD The first thing I noticed is it runs very very smooth. I ran Yosemite on here before and it was just so jittery and laggy I had to go back to Mavericks. It took ages for things to open, Safari was unstable and web pages had issues loading. El Capitan is just very smooth. I can tell Apple tested 10.11 on every Mac it supports and made sure it was optimized for the video card / chipset. But of corse it is a beta so I have run into a few issues. I get an error using Java applications saying it requires at least Java 1.6 which El Capitan does have but it just doesn't work. Yosemite also had this issue in it's beta stages though. Another problem I've had is broken apps. Menu Meters was the worst as it doesn't work at all. Other apps will still work but will be sort of unstable. For instance I can't have iTunes and Spotify open at once or Spotify will lose it's ****. In some other apps I've had freezes but never has an app not recovered from a freeze. Another small issue I've noticed is iTunes and Photos will not sync my iPhone 5s, but Mavericks has no issue syncing it on iTunes 12 and iPhoto '09. So other than the basic beta issues, it's exactly what Yosemite should've been. Better battery life, faster overall performance and a snappy UI that doesn't lag. I would highly recommend El Capitan to anyone with an older Mac such as mine when it's finally released. -Edit I've been playing with some new features and I have to say, I love the new version of Safari with the pinned tabs and Spotlight is actually more useful than I thought. Only two things I ~hate~ is I have to modify the Safari version number to 7.5.6 because 8.1 forces HTML 5 in YouTube. HTML 5 YouTube on my MacBook is awful. HTML 5 YouTube in general is awful. It forces 60FPS which slows down performance and most of the time it caps a video at 480p. Flash Player is still the best method for YouTube, YouTube is just not ready for HTML 5. But then again it wasn't ready for Google Plus either. Only other thing I dislike (Don't hate, just somewhat dislike) is the Photos app. On iPhoto I was able to simply select my iPhone and import the Pictures / Videos I selected. Now Photos can't interact with my iPhone at all. The photos on my iPhone just get uploaded to my photo stream and then Photos downloads pictures from there which takes for ever and that leaves me with no way to sync my Videos to my Mac without going back to Mavericks to use iPhoto '09 or going through iFunBox (which crashes most of the time when pulling video from an iPhone 4S running iOS 7 or above). Other than that I have had a way better experience on this MacBook over Yosemite and Mavericks. I'll post some pictures showing bench mark scores on 10.9 vs 10.11 sometime soon. In the end though, Mac OS X 10.5.8 Leopard is still the fastest OS I've used on this laptop.